THE INFANCY OF ANIMALS 



CHAPTER I 



INTRODUCTION 



Though the number of books on Natural History is legion, 

 one may search their pages in vain for any systematic 

 attempt to depict the earlier stages in the life-histories of 

 the creatures described therein. Even in works designed 

 for the use of the specialist one meets with the same neg- 

 lect. This is the more strange because such stages afford 

 us a key to much that mystifies when studying the later, 

 adult, phases of life. 



It is true that many learned treatises have been written 

 on the early, embryonic stages of development from man 

 himself downwards, but little has been done in regard to 

 the later " post-embryonic " stages, which so many 

 creatures have to pass through before they arrive at the age 

 of discretion, or, as we say, become adult. While few of 

 us have the time, or the requisite knowledge or technical 

 skill, to pursue the intricate mazes of embryology, most 

 of us can contrive to learn something at first hand on 

 the varied stages which animals of different kinds must 

 pass through in the juvenile period of their life-history. 

 Whatever group of animals we survey in this regard, we 

 shall find new themes for contemplation, new aspects of 

 I 



